The present invention relates to an arrangement for providing access between user equipment (such as for example cordless telephones) which are connected to base stations via radio and a switching arrangement of a telecommunications network wherein at least one access network is provided which interfaces the switching arrangement(s) via at least one interface.
The invention further relates to a telecommunications system comprising a telecommunications network and a number of user stations connected via radio to a number of base stations, said telecommunications network comprising a number of switching arrangements, the system further comprising at least one access network connecting to the switching arrangements over at least one interface.
Still further the invention relates to a method for providing access between a number of user stations connected via radio to a number of base stations and a local exchange of a telecommunications network with a number of switching arrangements wherein access is provided via an access network connecting to the switching arrangements of the telecommunications network.
It is becoming more and more interesting to use radio in telecommunication networks. Services of interest are for example Cordless Terminal Mobility (CTM) and Radio in the Local Loop (RLL). The network architecture of existing public switched communication networks is not such as to enable handling of users connected via radio, for example via the DECT air interface (Digital European Cordless Telephone System) to the local exchanges of the public switched systems, among others since these users are movable within the network. Today there is no standardized interface for interfacing CTM services to the local exchanges. This means that there is no interface handling the mobility of these subscribers in the network for the necessary transmission between local exchanges and the subscriber. The V5.1 interface standardized by ETSI, European Telecommunications Standard Institute, ETS 300 324-1, interconnects an Access Network (AN) with a Local Exchange (LE) of a Public Switched Telecommunications Network and it comprises a 2048 kbit/s data link for multiplexing of up to 30 PSTN or 15 ISDN-BA (Basic Access) accesses. This interface can however not take care of the mobility of the subscribers as referred to above. For traditional users there is a fixed relation between the directory number (DN) and the equipment to the User Network Interface (UNI). For the handling of movable users which can be anywhere in the network, the connection of the user and used base stations (when referring to the DECT system, these are known as Radio Fixed Parts RFP), is not sufficiently flexible and moreover the traffic concentration of the interface can not be handled.
U.S. Pat. No. 5,040,177 describes an access network for a cordless telephone service. This access network comprises a distribution network with base stations connected by cable to the public switched network and digital cordless telephones. Each telephone is connected by radio to the same base station throughout the duration of a call. Moreover the access network comprises a service control point network with network service control points connected to the public switched network. Each point comprises a data base of cordless telephone service subscribers for processing a number of functions in real time. The service control point network moreover comprises a managing service control point controlling the databases. The service control point network has the architecture of an intelligent network. Each base station is connected to the public switched network via a 2B+D or a 30B+D type channel. The public network is an integrated services network. A conversion is effected to and from ISDN protocol.
However, none of the known systems works as satisfactorily or is as simple as desired e.g. relating to fulfilment of requirements for example as to traffic concentration, ability of handling handovers without generating any necessary signalling to the switching arrangement (such as a local exchange) of the public switched communications network etc.